Yussuf struck after just four minutes, added another before half-time and despite Scott Rendell pulling one back after the break, Yussuf later bagged his hat-trick to restore their two-goal advantage.
The Shots manager was fuming at full-time and sympathised with supporters who made the long trip north.
"We gave ourselves a mountain to climb yet again after four minutes. Our away supporters deserve better than that today. I said to the players that it was a very, very poor performance. My words were that it was 'pathetic' and I stand by that.
"No where near what we want to do. It's been coming, the last four or five games we've not shown what we're about, we've not shown our way, our identity, our DNA whatever you want to call it.
"We didn't deserve anything. It's arguably our worst performance since we've been together."